I currently have a custom SF M4 body that needs a head. I found a complete M500, used, for cheap. Will the M500 head fit on the M4 body? From the research I've done, the M500 can use the M3 turbo head but I cannot figure out if the diameter/threads of the M3 turbo head are the same as the M4 Devastator head. Once I have the head, I'll eventually convert it to LED.